Paternal knockdown of (cytosine‐5‐)‐methyltransferase ( ) increases offspring susceptibility to infection in red flour beetles

Schulz NKE, Mohamed FF, Lo LK, Peuß R, de Buhr MF, Kurtz J. Paternal knockdown of (cytosine‐5‐)‐methyltransferase ( ) increases offspring susceptibility to infection in red flour beetles. Insect Molecular Biology. 2022;31(6):711-721.Intergenerational effects from fathers to offspring are increasingly reported from diverse organisms, but the underlying mechanisms remain speculative. Paternal trans‐generational immune priming (TGIP) was demonstrated in the red flour beetleTribolium castaneum: non‐infectious bacterial exposure of fathers protects their offspring against an infectious challenge for at least two generations. Epigenetic processes, such as cytosine methylation of nucleic acids, have been proposed to enable transfer of information from fathers to offspring. Here we studied a potential role in TGIP of theDnmt2gene (renamed asTrdmt1in humans), which encodes a highly conserved enzyme that methylates different RNAs, including specific cytosines of a set of tRNAs.Dnmt2has previously been reported to be involved in intergenerational epigenetic inheritance in mice and protection against viruses in fruit flies. We first studied gene expression and found thatDnmt2is expressed in various life history stages and tissues ofT. castaneum, with high expression in the reproductive organs. RNAi‐mediated knockdown ofDnmt2in fathers was systemic, slowed down offspring larval development and increased mortality of the adult offspring upon bacterial infection. However, these effects were independent of bacterial exposure of the fathers. In conclusion, our results point towards a role ofDnmt2for paternal effects, while elucidation of the mechanisms behind paternal TGIP needs further studies

Hypericum perforatum and Its Ingredients Hypericin and Pseudohypericin Demonstrate an Antiviral Activity against SARS-CoV-2

For almost two years, the COVID-19 pandemic has constituted a major challenge to human health, particularly due to the lack of efficient antivirals to be used against the virus during routine treatment interventions. Multiple treatment options have been investigated for their potential inhibitory effect on SARS-CoV-2. Natural products, such as plant extracts, may be a promising option, as they have shown an antiviral activity against other viruses in the past. Here, a quantified extract of Hypericum perforatum was tested and found to possess a potent antiviral activity against SARS-CoV-2. The antiviral potency of the extract could be attributed to the naphtodianthrones hypericin and pseudohypericin, in contrast to other tested ingredients of the plant material, which did not show any antiviral activity. Hypericum perforatum and its main active ingredient hypericin were also effective against different SARS-CoV-2 variants (Alpha, Beta, Delta, and Omicron). Concerning its mechanism of action, evidence was obtained that Hypericum perforatum and hypericin may hold a direct virus-blocking effect against SARS-CoV-2 virus particles. Taken together, the presented data clearly emphasize the promising antiviral activity of Hypericum perforatum and its active ingredients against SARS-CoV-2 infections